Snippets that cannot be expanded are also listed in the popup menu

[ichitera]

Some of the snippets shown by asyncomplete-neosnippet.vim in the popup menu cannot be expanded.

This is the screencast for explanation:

In this screencast, I typed a dot, and asyncomplete-neosnippet.vim opened the popup menu.
I typed <C-k> to expand selected snippets, but the snippets did not be expanded.

This is the vimrc used in the above screencast:

language C

if !filereadable('plug.vim')
  silent !curl --insecure -fLo plug.vim
    \  https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim
endif

source plug.vim

call plug#begin('plugged')
Plug 'Shougo/neosnippet.vim'
Plug 'Shougo/neosnippet-snippets'
Plug 'prabirshrestha/async.vim'
Plug 'prabirshrestha/asyncomplete.vim'
Plug 'prabirshrestha/asyncomplete-neosnippet.vim'
call plug#end()

call asyncomplete#register_source(asyncomplete#sources#neosnippet#get_source_options({
    \ 'name': 'neosnippet',
    \ 'whitelist': ['*'],
    \ 'completor': function('asyncomplete#sources#neosnippet#completor'),
    \ }))
imap <C-k>     <Plug>(neosnippet_expand_or_jump)
smap <C-k>     <Plug>(neosnippet_expand_or_jump)
xmap <C-k>     <Plug>(neosnippet_expand_target)

The way to reporoduce:

1. execute vim.exe -u vimrc -N
2. type a dot .
3. select an item by <C-n>
4. execute <Plug>(nesonippet_expand_or_jump) by <C-k>
5. (the issue occurs; some items will not be expanded)

Environment:

• OS: Windows 10 64bit
• Vim: 8.1.1174
• async.vim: f30145
• asyncomplete.vim: db0cd
• asyncomplete-neosnippet.vim: 9d8956